This invention relates in general to the use of pesticides, such as those from the avermectin family, and an organosilicone surfactant as a solvent for the pesticide.
Standard pesticide formulations such as those disclosed in U.S. Pat. Nos. 5,558,806 and 5,104,647, issued to Policello et al., incorporated herein by reference, utilize active ingredients such as abamectin solubilized in a formulation with a 1:1 ratio of an organosilicone surfactant such as polysiloxane with another ingredient such as Tergitol(copyright) xe2x80x9cTMN-6xe2x80x9d (trimethylnononal ethoxylate). However, when the active ingredient such as abamectin has been solubilized in the polysiloxane:TMN6 blend, the spreading of the material is detrimental to the efficacy of the pesticide.
Other pesticide formulations, such as those disclosed in U.S. Pat. No. 4,560,677 issued to Dybas, incorporated herein by reference, include an avermectin pesticide in combination with an agricultural spray oil which is added in the interest of extending the time period over which the pesticide will be effective. However, while some extension of the period of effectiveness is added by the use of the agricultural spray oil, the added time period is only achieved by virtue of the addition of the expensive spray oil, and thus the combination of avermectin with spray oils does not constitute an efficient or cost effective manner of achieving adequate coverage of pesticides for an extended period of time.
There is thus a distinct need in the field of pesticides to develop new formulations with solvents that result in a more efficient and efficacious pesticide, and which can be utilized in a more productive manner so as to reduce or eliminate the possibility of deleterious attack on plant crops by pests such as nematodes or mites. In addition, there is a distinct need in the field of pesticides to develop new formulations which can provide an effective and inexpensive pesticide for elongated periods of time without the need for the additional expense and complication of adding an agricultural spray oil.
Accordingly, it is thus an object of the present invention to provide a novel pesticide composition including an active ingredient such as those compounds of the avermectin family and an organosilicone surfactant as the solvent for the pesticide.
It is further an object of the present invention to provide a novel pesticide which utilizes an organosilicone surfactant as a solvent so as to provide superior mite control when compared to standard formulations at the same concentration of the active ingredient.
It is still further an object of the present invention to provide a novel pesticide composition which can be used to control mites in citrus and other crops, and which can also be utilized to control a wide variety of insects using a pesticide concentration that is less than those concentrations used in previous pesticide formulations.
It is even further an object of the present invention to provide a novel pesticide composition which can be used to provide extended and inexpensive crop treatment without the need for the expensive and complex addition of an agricultural spray oil.
These and other objects are achieved by virtue of the present invention which comprises a novel pesticide formulation comprising a pesticide, such as those of the avermectin family, and an organosilicone surfactant, such as polysiloxane, as the solvent for the pesticide. In addition, a method is provided wherein pests can be reduced or eliminated from crops by virtue of the use of the pesticide formulation of the present invention. The use of the organosilicone surfactant as a solvent in conjunction with the avermectin pesticide in accordance with the present invention has resulted in control of pests such as mites in substantially greater amounts for a longer period of time than has been accomplishing using prior art formulations including those which use similar concentrations of the active ingredient or those which use the pesticide in combination with an agricultural spray oil.
These and other features of the present invention as set forth in, or will become obvious from, the detailed description of the preferred embodiments provided hereinbelow.
In accordance with the present invention, an improved pesticide is provided which involves the use of a variety of pesticides, such as those of the avermectin family, with an organosilicone surfactant, such as polysiloxane, as a solvent for the pesticide. In the preferred embodiment of the present invention, the pesticide that is used is one from the avermectin family of pesticides whose structures are closely related complex 16-membered lactones which exhibit synergistic effects when dissolved in the organosilicone material. These avermectin pesticides include compounds such as these have been disclosed in U.S. Pat. No. 4,560,677, incorporated herein by reference. The avermectin pesticide useful in the present invention thus may be any avermectin pesticide well known in the art, such as the avermectin compounds disclosed in U.S. Pat. No. 4,560,677 (issued to Dybas), or others well known in the art. One such particularly preferred pesticide is known as abamectin (or avermectin B-1) which can be utilized in accordance with the invention. Other avermectins useful in accordance with the invention are those classified as avermectin A1a, A1b, A2a, A2b, B1b, B1b, B2a, and B2b, having the formulas as described in U.S. Pat. No. 4,560,677.
However, although the present invention is known to be particularly useful with pesticides of the avermectin family, such as abamectin, the present invention will be useful with any pesticide that is compatible for use with an organosilicone surfactant. As will be recognized by one of ordinary skill in this art, a variety of pesticides may be employed in accordance with the present invention to accomplish crop protection against a variety of insect and other pests, and thus the particular pesticide to be used with the organosilicone surfactant of the invention will be dependent upon the type of crop involved and the particular pest for which is sought to be protected against. The present invention is designed to control a wide variety of pests that usually damage plants or crops, including nematodes, spider mites, other mites, and other common pests typically faced by plant species. The plants that can be protected using the present invention include numerous plants subject to pests including food crops and ornamental plants as well.
In the preferred embodiment, the pesticide composition in accordance with the present invention is prepared by placing an amount of the active ingredient, such as a pesticide of the avermectin family, in the range of approximately 0.001 to 25% by weight, the solubility limit of the active ingredient, with a preferred range of about 1-5%, into an organosilicone surfactant such as polysiloxane which will comprise approximately 75 to 99.999% by weight of the composition. As recited above, it is intended to indicate that these preferred weight percent amounts in the composition are those amounts which will be present in the resulting composition prior to any dilution. In this preferred embodiment, the avermectin family compound and the organosilicone surfactant are mixed in these weight percentages, and the resulting composition or concentrate may be utilized in this form, as would be the case for use by individuals in plants or gardens found in or around the home. However, when used in more industrial applications, such as for fields or crops, or for use with plants or foliage in a larger scale, this concentrated form of the composition of the invention may be diluted as necessary with an aqueous fluid, e.g., water, to any desired amount. Depending on the size of the actual application, ranging from relatively small areas to large fields of crops or other plants, the diluent, such as water, may be added in amounts ranging from a few liters to hundreds or thousands of gallons of aqueous liquid.
In any event, the avermectin:organosilicone ratio in the final preferred composition will thus range from about 0.001:100 (1:100,000) to about 25:75 (1:3) by weight. In the particularly preferred embodiment, the avermectin:organosilicone ratio will range from about 1:100 to about 5:75 (1:15) by weight.
In a particularly preferred embodiment utilizing an avermectin compound as an active ingredient, approximately 1-5 grams of avermectin is mixed into about 90-110 grams of polysiloxane. If the active material is less than 100% in purity, it is preferred that the material be corrected and the polysiloxane level be concomitantly reduced. In the preferred process of preparing the pesticide composition of the invention, this mixture is blended until the avermectin is dissolved in the polysiloxane. The polysiloxane preferably may also be warmed (e.g., to about 40xc2x0 C. or other suitable temperature depending on the precise ingredients used) in order to facilitate and expedite the dissolution process. Finally, as set forth above, the formulation may be diluted with an appropriate amount of a suitable aqueous liquid such as water.
One particularly preferred polysiloxane which may be used in the invention is the polysiloxane known as trisiloxane-8-ethoxylate, but any polysiloxane that may be useable on plants and crops is suitable for use in the present invention. One preferred polysiloxane formulation utilized as the organosilicone surfactant of the invention is known as Silwet-77, and this formulation includes polyalkyleneoxide-modified heptamethyltrisiloxane at a level of about 84%, and allyloxypolyethyleneglycol methyl ether at a level of 16%. In preparing the composition of the present invention, as indicated above, an amount of the avermectin compound in the range of about 0.001% to about 25% by weight of the composition, and preferably about 1 to 5% of the overall composition, should be utilized to prepare the desired pesticide formulation. However, as set forth above, with regard to the use of the active avermectin ingredient, e.g., abamectin, if this active ingredient is utilized in a percentage of less than 100%, the material is preferably corrected and the polysiloxane is concomitantly reduced.
Once prepared in the manner stated above, or in any other conventional manner that would be employed to prepare a pesticide composition from ingredients as recited above, the avermectin pesticide compositions may be applied to crops in any suitable manner based on the size and nature of the plants or crops to be treated. The application of the pesticides of the present invention may be conducted in any of a number of suitable ways well known in this field. Such application procedures include spraying, pouring, hosing, or other conventional methods for applying a pesticide utilizing conventional equipment such as a spray hose, hand mister, crop duster, etc. In the preferred method, individual plants or crops are sprayed until dripping with the pesticide formulation of the present invention, and this can be done as many times as necessary for the particular plant or crop, e.g., daily, weekly, etc. depending on the plant or crop and the likelihood of pest infestation.
It is thus contemplated that the amount applied to the plants or crops will be that amount effective to reduce or eliminate damage to the plant or crop by pests such as mites. This effective amount will differ depending on the specific plant or crop being treated, as well as with the varying environmental conditions, e.g., temperature, water level, moisture levels, etc., that such plants or crops will be subject to. In addition, in circumstances where pest infestation is more likely, applications of the present pesticide may be increased as needed.
As utilized in the manner set forth above, the pesticide formulation of the present invention can thus be utilized advantageously to control a wide variety of insects using a pesticide concentration that is less than those concentrations used in previous pesticide formulations.
It is thus submitted that the foregoing embodiments are only illustrative of the claimed invention, and alternative embodiments well known or obvious to one skilled in the art not specifically set forth above also fall within the scope of the claims.